Minimally invasive glaucoma surgical instrument and method

ABSTRACT

Apparatuses and methods for the treatment of glaucoma are provided. The instrument uses either cauterization, a laser to ablate, sonic or ultrasonic energy to emulsify, or mechanical cutting of a portion of the trabecular meshwork. The instrument may also be provided with irrigation, aspiration, and a footplate. The footplate is used to enter Schlemm&#39;s canal, serves as a guide, and also protects Schlemm&#39;s canal.

CROSS-REFERENCE TO THE RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional ApplicationSerial No. 60/263,617, filed Jan. 18, 2001, the disclosure of which isherein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a new glaucoma surgicalinstrument and method, and, in particular, removal of the trabecularmeshwork by mechanical cautery, vaporization or other tissue destructionmeans optionally coupled to an instrument with infusion, aspiration, anda footplate.

[0004] 2. Description of the Related Art

[0005] Aqueous is a clear, colorless fluid that fills the anterior andposterior chambers of the eye. The aqueous is formed by the ciliary bodyin the eye and supplies nutrients to the lens and cornea. In addition,the aqueous provides a continuous stream into which surrounding tissuescan discharge the waste products of metabolism.

[0006] The aqueous produced in the ciliary process circulates from theposterior chamber to the anterior chamber of the eye through the pupiland is absorbed through the trabecular meshwork, a plurality ofcrisscrossing collagen cords covered by endothelium. Once through thetrabecular meshwork, the aqueous passes through Schlemm's canal intocollector channels that pass through the scleral and empty into theepiscleral venous circulation. The rate of production in a normal eye istypically 2.1 μL/min. Intraocular pressure in the eye is maintained bythe formation and drainage of the aqueous. All the tissues within thecorneoscleral coat covering the eyeball are subject to this pressure,which is higher than pressure exerted on tissues at other locations inthe body.

[0007] Glaucoma is a group of diseases characterized by progressiveatrophy of the optic nerve head leading to visual field loss, andultimately, blindness. Glaucoma is generally associated with elevatedintraocular pressure, which is an important risk factor for visual fieldloss because it causes further damage to optic nerve fibers. Othercauses of glaucoma may be that the nerve is particularly vulnerable tothe pressure due to poor local circulation, tissue weakness orabnormality of structure. In a “normal” eye, intraocular pressure rangesfrom 10 to 21 mm mercury. In an eye with glaucoma, this pressure canrise to as much as 75 mm mercury.

[0008] There are several types of glaucoma, including open and closedangle glaucoma, which involve the abnormal increase in intraocularpressure, primarily by obstruction of the outflow of aqueous humor fromthe eye, or, less frequently, by over production of aqueous humor withinthe eye. The most prevalent type is primary open angle glaucoma in whichthe aqueous humor has free access to the irridocorneal angle, butaqueous humor drainage is impaired through obstruction of the trabecularmeshwork. In contrast, in closed angle glaucoma, the irridocorneal angleis closed by the peripheral iris. The angle block can usually becorrected by surgery. Less prevalent types of glaucoma include secondaryglaucomas related to inflammation, trauma, and hemorrhage.

[0009] Aqueous humor is similar in electrolyte composition to plasma,but has a lower protein content. The aqueous humor keeps the eyeballinflated, supplies the nutritional needs of the vascular lens and corneaand washes away metabolites and toxic substances within the eye. Thebulk of aqueous humor formation is the product of active cellularsecretion by nonpigmented epithelial cells of the ciliary process fromthe active transport of solute, probably sodium, followed by the osmoticflow of water from the plasma. The nonpigmented epithelial cells of theciliary process are connected at their apical cell membranes by tightjunctions. These cells participate in forming the blood/aqueous barrierthrough which blood-borne large molecules, including proteins, do notpass.

[0010] Intraocular pressure (IOP) is a function of the differencebetween the rate at which aqueous humor enters and leaves the eye.Aqueous humor enters the posterior chamber by three means: 1) activesecretion by nonpigmented epithelial cells of the ciliary process; 2)ultrafiltration of blood plasma; and 3) diffusion. Newly formed aqueoushumor flows from the posterior chamber around the lens and through thepupil into the anterior chamber; aqueous humor leaves the eye by 1)passive bulk flow at the irridocorneal angle by means of theuveloscleral outflow, or by 2) active transportation through thetrabecular meshwork, specifically the juxta canalicar portion. Anychange in 1), 2), or 3) will disturb aqueous humor dynamics and likelyalter intraocular pressure.

[0011] Primary open angle glaucoma is caused by a blockage in thetrabecular meshwork. This leads to an increase in intraocular pressure.The major obstruction is at the juxta-canalicular portion which issituated adjacent to Schlemm's canal. In infants a goniotomy or atrabeculotomy can be performed. In goniotomy or trabeculotomy a smallneedle or probe is introduced into Schlemm's canal and the trabecularmeshwork is mechanically disrupted into the anterior chamber.Approximately 90°-120° of trabecular meshwork can be disrupted. Theanatomical difference between congenital glaucoma and adult glaucoma isthat in congenital glaucoma the ciliary body muscle fibers insert intothe trabecular meshwork and once disrupted the trabecular meshwork ispulled posteriorly allowing fluid to enter Schlemm's canal and to beremoved through the normal collector channels that are present in thewall of Schlemm's canal. In adults the trabecular meshwork tears butremains intact and reattaches to the posterior scleral wall of Schlemm'scanal blocking the collector channels.

[0012] Most treatments for glaucoma focus on reducing intraocularpressure. Treatment has involved administration of beta-blockers such astimolol to decrease aqueous humor production, adranergic agonists tolower intraocular pressure or diuretics such as acetazolamide to reduceaqueous production, administration of miotic eyedrops such aspilocarpine to facilitate the outflow of aqueous humor, or prostaglandinanalogs to increase uveoscleral outflow. Acute forms of glaucoma mayrequire peripheral iridectomy surgery to relieve pressure where drugtherapy is ineffective and the patient's vision is at immediate risk.Other forms of treatment have included physical or thermal destruction (“cyclodestruction”) of the ciliary body of the eye, commonly by surgeryor application of a laser beam, cryogenic fluid or high frequencyultrasound.

[0013] In guarded filtration surgery (trabeculectomy), a fistula createdthrough the limbal sclera is protected by an overlying partial thicknesssutured scleral flap. The scleral flap provides additional resistance toexcessive loss of aqueous humor from the eyeball, thereby reducing therisk of early postoperative hypotony.

[0014] In accordance with one recently introduced procedure, a fullthickness filtering fistula may be created by a holmium laser probe,with minimal surgically induced trauma. After retrobulbar anesthesia, aconjunctival incision (approximately 1 mm) is made about 12-15 mmposterior to the intended sclerostomy site, and a laser probe isadvanced through the sub-conjunctival space to the limbus. Then,multiple laser pulses are applied until a full thickness fistula iscreated. This technique has sometimes resulted in early hypotony onaccount of a difficulty in controlling the sclerostomy size. Inaddition, early and late iris prolapse into the sclerostomy has resultedin abrupt closure of the fistula and eventual surgical failure. Further,despite its relative simplicity, the disadvantage of this procedure, aswell as other types of glaucoma filtration surgery, is the propensity ofthe fistula to be sealed by scarring.

[0015] Various attempts have been made to overcome the problems offiltration surgery, for example, by using ophthalmic implant instrumentssuch as the Baerveldt Glaucoma Implant. Typical ophthalmic implantsutilize drainage tubes so as to maintain the integrity of the openingsformed in the eyeball for the relief of the IOP.

[0016] Typical ophthalmic implants suffer from several disadvantages.For example, the implants may utilize a valve mechanism for regulatingthe flow of aqueous humor from the eyeball; defects in and/or failure ofsuch valve mechanisms could lead to excessive loss of aqueous humor fromthe eyeball and possible hypotony. The implants also tend to clog overtime, either from the inside by tissue, such as the iris, being suckedinto the inlet, or from the outside by the proliferation of cells, forexample by scarring. Additionally, the typical implant insertionoperation is complicated, costly and takes a long time and is reservedfor complicated glaucoma problems.

[0017] There are many problems, however, in effectively treatingglaucoma with long term medicinal or surgical therapies. One problem isthe difficulty in devising means to generate pharmacologically effectiveintraocular concentrations and to prevent extraocular side effectselicited by a systemic administration. Many drugs are administeredtopically or locally. The amount of a drug that gets into the eye is,however, only a small percentage of the topically applied dose becausethe tissues of the eye are protected from such substances by numerousmechanisms, including tear turnover, blinking, conjunctival absorptioninto systemic circulation, and a highly selective corneal barrier.

[0018] Pharmacological treatment is prohibitively expensive to a largemajority of glaucoma patients. In addition, many people afflicted withthe disease live in remote or undeveloped areas where the drugs are notreadily accessible. The drugs used in the treatment often haveundesirable side effects and many of the long-term effects resultingfrom prolonged use are not yet known. Twenty-five percent of patients donot use their medications correctly.

[0019] Glaucoma is a progressively worsening disease, so that afiltration operation for control of intraocular pressure may becomenecessary. Present surgical techniques to lower intraocular pressure,when medication fails to decrease fluid flow into the eye or to increasefluid outflow, include procedures that permit fluid to drain from withinthe eye to extraocular sites by creating a fluid passageway between theanterior chamber of the eye and the potential supra-scleral/sub-Tenon'sspace, or, alternatively, into or through the Canal of Schlemm (see,e.g., U.S. Pat. No. 4,846,172). The most common operations for glaucomaare glaucoma filtering operations, particularly trabeculectomy. Theseoperations involve creation of a fistula between the subconjunctivalspace and the anterior chamber. This fistula can be made by creating ahole at the limbus by either cutting out a portion of the limbal tissueswith either a scalpel blade or by burning with a cautery through thesubconjunctival space into the anterior chamber. Fluid then filtersthrough the fistula and is absorbed by episcleral and conjunctival. Inorder for the surgery to be effective, the fistula must remainsubstantially unobstructed. These drainage or filtering procedures,however, often fail by virtue of closure of the passageway resultingfrom the healing of the very wound created for gaining access to thesurgical site. Failures most frequently result from scarring at the siteof the incisions in the conjunctiva and the Tenon's capsule. The surgeryfails immediately in at least 15% of patients, and long term in a muchhigher percentage. Presently, this consequence of trabeculectomy,closure of the passageway, is treated with 5 fluorouracil and Mitomycin_C, which apparently prevent closure by inhibiting cellularproliferation. These drugs, however, are highly toxic and haveundesirable side effects, including scleral melting, hypotony, leaks,and late infections.

[0020] Other surgical procedures have been developed in an effort totreat victims of glaucoma. An iridectomy, removal of a portion of theiris, is often used in angle-closure glaucoma wherein there is anocclusion of the trabecular meshwork by iris contact. Removal of a pieceof the iris then gives the aqueous free passage from the posterior tothe anterior chambers in the eye. The tissue of the eye can grow back tothe pre-operative condition, thereby necessitating the need for furthertreatment.

[0021] In view of the limited effectiveness of treatment options, thereis, therefore, a need to develop more effective treatments for glaucoma.

SUMMARY OF THE INVENTION

[0022] The present invention is a surgical instrument and minimallyinvasive surgical method to remove at least a portion of the trabecularmeshwork of the eye, providing for aqueous drainage in the treatment ofglaucoma.

[0023] A preferred embodiment of the present invention involvesinserting a surgical instrument through a small corneal incisiontranscamerally under direct visualization to ablate the trabecularmeshwork. The instrument may include a foot plate, such that theinstrument can penetrate the trabecular meshwork into Schlemm's canal.The footplate may also act as a protective device for the endothelialcells and collector channels lining the scleral wall of Schlemm's canal.The instrument may also comprise an infusion system and aspirationsystem. Infusion maintains and deepens the anterior chamber so that easyaccess of the angle of the eye is obtained to the trabecular meshworkand Schlemm's canal. Infusion also allows fluid to flow out to thecollector channels whilst the surgery is being performed, thus keepingthe surgical site blood free. Aspiration is designed to remove ablatedtissue, gas and bubble formation, and all intraocular debris generated.The aspiration may be directly linked to either a cutting mechanism,such as a guillotine cutting machine, laser probe, a piezo-electriccrystal producing sonic or ultrasonic energy, or cautery element. Thesemodalities are capable of substantially complete tissue removal bymechanical means, cautery, vaporization, or other tissue destructiontechniques.

[0024] The surgical instrument is used to perform a goniectomyprocedure, by removing a portion of the trabecular meshwork consistingof the pigmented trabecular meshwork, allowing free access of aqueousfrom the anterior chamber through to the scleral portion of Schlemm'scanal that contains the endothelial cells and most importantly thecollector channels that lead back to the episcleral venous system.

[0025] In another embodiment, a Schlemmectomy surgical procedure,similar to a trabeculotomy, a schlemmectomy probe is inserted intoSchlemm's canal under direct visualization through a scleral incision,such that the surface of the instrument faces the trabecular meshworkand the tissue comprising the pigmented and a portion of thenonpigmented trabecular meshwork facing into Schlemm's canal is removedby a cautery element, radio-frequency electrode, or an ultrasoundtransducer formed from a piezo-electric crystal.

[0026] This instrument is advantageous because it combines existingprocedures with new technology, providing a simple solution for glaucomatreatment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a cross sectional schematic diagram of a human eye.

[0028]FIG. 2 is a cross sectional schematic diagram which shows aqueousflow into and through the anterior chamber in a human eye.

[0029]FIGS. 3a-d shows diagrammatically the progression of thedeformation of the lamina cribrosa in glaucoma.

[0030]FIGS. 4a-c show diagrammatically the steps of performing agoniectomy.

[0031]FIGS. 5a-d show diagrammatically the steps of performing atrabeculodialysis.

[0032]FIGS. 6a-e show diagrammatically the steps of a trabeculotomyprocedure using a probe of a preferred embodiment.

[0033]FIG. 7 is a perspective view which shows a goniectomy cauteryprobe of a preferred embodiment.

[0034]FIG. 8 is a cross-sectional schematic diagram which shows thegoniectomy cautery probe of FIG. 7.

[0035]FIG. 9 is a cross sectional schematic diagram which shows anotherembodiment of the goniectomy cautery probe of FIG. 7.

[0036]FIG. 10a is a detailed view which shows the probe tip of thegoniectomy cautery probe of FIG. 7.

[0037]FIG. 10b is a cross-sectional schematic diagram which shows theprobe tip of the goniectomy cautery probe of FIG. 7.

[0038]FIG. 11 a is a detailed view which shows the probe tip of thegoniectomy cautery probe of FIG. 7.

[0039]FIG. 11b is a cross-sectional schematic diagram which shows theprobe tip of the goniectomy cautery probe of FIG. 7.

[0040]FIG. 12a is a detailed view which shows the probe tip of thegoniectomy cautery probe of FIG. 7.

[0041]FIG. 12b is a cross-sectional schematic diagram which shows theprobe tip of the goniectomy cautery probe of FIG. 7.

[0042]FIG. 13 is a perspective view which shows a goniectomy cauteryprobe of a preferred embodiment.

[0043]FIG. 14 is a perspective view which shows a goniectomy cauteryprobe of a preferred embodiment.

[0044]FIG. 15a is a detailed view which shows the probe tip of thegoniectomy cautery probe of FIG. 13.

[0045]FIG. 15b is a cross-sectional schematic diagram which shows theprobe tip of the goniectomy cautery probe of FIG. 13.

[0046]FIG. 16a is a detailed view which shows the probe tip of thecautery probe of FIG. 14.

[0047]FIG. 16b is a cross-sectional schematic diagram which shows theprobe tip of the cautery probe of FIG. 14.

[0048]FIG. 17 shows a schematic of a circuit diagram of a preferredembodiment of a goniectomy probe.

[0049]FIG. 18 is a perspective view which shows a goniectomy probe.

[0050]FIG. 19 is a cross-sectional schematic diagram which shows anembodiment of the probe of FIG. 18.

[0051]FIG. 20 is a cross-sectional schematic diagram which shows anembodiment of the probe of FIG. 18.

[0052]FIG. 21 is a cross-sectional schematic diagram which shows anembodiment of the probe of FIG. 18.

[0053]FIG. 22 is a cross-sectional schematic diagram which shows anembodiment of the probe of FIG. 18.

[0054]FIG. 23 is a cross-sectional schematic diagram which shows anembodiment of the probe of FIG. 18.

[0055]FIG. 24a is a perspective view which shows a preferred embodimentof a laser goniectomy probe.

[0056]FIG. 24b is a perspective view which shows a preferred embodimentof a laser goniectomy probe.

[0057]FIG. 25 is a cross sectional schematic diagram of the lasergoniectomy probe of FIG. 24a.

[0058]FIG. 26 is a cross sectional schematic diagram of the lasergoniectomy probe of FIG. 24b.

[0059]FIG. 27 is a cross sectional schematic diagram of the lasergoniectomy probe of FIG. 24b.

[0060]FIG. 28 is a perspective view which shows a Schlemmectomy probe ofa preferred embodiment.

[0061]FIGS. 29a-c are detailed views which show the probe tip of theprobe of FIG. 28.

[0062]FIG. 30 is a perspective view of an alternative preferredembodiment of the probe of FIG. 28.

[0063]FIGS. 31 a, b, c are detailed views of the probe tip of FIG. 30.

[0064]FIGS. 32a, b are detailed views which show the probe tip of theprobe of FIG. 30.

[0065]FIG. 33a is a detailed view which shows the probe tip of the probeof FIG. 30.

[0066]FIG. 33b is a cross-sectional schematic diagram which shows theprobe tip of the probe of FIG. 30.

[0067]FIG. 34a is a detailed view which shows the probe tip of the probeof FIG. 30.

[0068]FIG. 34b is a cross-sectional schematic diagram which shows theprobe tip of the probe of FIG. 30.

[0069]FIG. 35a is a detailed view which shows the probe tip of the probeof FIG. 30.

[0070]FIG. 35b is a cross-sectional schematic diagram which shows theprobe tip of the probe of FIG. 30.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0071] Referring to FIG. 1, relevant structures of the eye will bebriefly described, so as to provide background for the anatomical termsused herein. Certain anatomical details, well known to those skilled inthe art, have been omitted for clarity and convemence.

[0072] As shown in FIG. 1, the cornea 103 is a thin, transparentmembrane which is part of the outer eye and lies in front of the iris104. The cornea 103 merges into the sclera 102 at a juncture referred toas the limbus 108. A layer of tissue called bulbar conjunctiva 106covers the exterior of the sclera 102. The bulbar conjunctiva 106 isthinnest anteriorly at the limbus 108 where it becomes a thin epitheliallayer which continues over the cornea 103 to the corneal epithelium. Asthe bulbar conjunctiva 106 extends posteriorly, it becomes moresubstantial with greater amounts of fibrous tissue. The bulbarconjunctiva 106 descends over Tenon's capsule approximately 3 mm fromthe limbus 108. Tenon's capsule is thicker and more substantialencapsulatory tissue which covers the remaining portion of the eyeball.The subconjunctival and sub-Tenon's capsule space become one when thesetwo tissues meet, approximately 3 mm from the limbus. The ciliary bodyor ciliary process 110 is part of the uveal tract. It begins at thelimbus 108 and extends along the interior of the sclera 102. The choroid112 is the vascular membrane which extends along the retina back towardsthe optic nerve. The anterior chamber 114 of the eye is the spacebetween the cornea 103 and a crystalline lens 116 of the eye. Thecrystalline lens of the eye is situated between the iris 104 and thevitreous body 120 and is enclosed in a transparent membrane called alens capsule 122. The anterior chamber 114 is filled with aqueous humor118. The trabecular meshwork 121 removes excess aqueous humor 118 fromthe anterior chamber 114 through Schlemm's canal 124 into collectorchannels which merge with blood-carrying veins to take the aqueous humor118 away from the eye.

[0073] As shown in FIG. 2, the flow of aqueous 118 is from the posteriorchamber, through the pupil, into the anterior chamber 114.

[0074]FIGS. 3a-d show longitudinal sections through the optic nervehead, illustrating the progressive deepening of the cup 302 in the nervehead from normal to advanced glaucoma. FIG. 3a shows a normal nerve andFIG. 3d shows an effected nerve in advanced glaucoma. As the cup 302deepens and the lamina cribrosa 306 becomes more curved, axons 304passing through the lamina 306 are subject to kinking and pressure asthey make their way through the lamina 306.

[0075] Goniotomy

[0076]FIGS. 4a-c show the steps for performing a goniotomy procedure. Asshown in FIG. 4a, locking forceps 406 are typically used to grasp theinferior and superior rectus muscles. A goniotomy lens 408 is positionedon the eye. A goniotomy knife 400 is inserted from the temporal aspectbeneath the goniotomy lens and viewed through a microscope. The corneais irrigated with balanced salt solution. The surgeon positions thegoniotomy lens 408 on the cornea, holding the lens 408 with an angled,toothed forceps 406 placed into the two dimples at the top of the lens408.

[0077] The surgeon places the goniotomy knife 400 into and through thecornea 1.0 mm anterior to the limbus, maintaining the knife 400 parallelto the plane of the iris (FIG. 4b). Slight rotation of the knife 400facilitates smooth penetration into the anterior chamber without asudden break through the cornea. The surgeon continues to gently applypressure and rotate the goniotomy knife 400, directing it across thechamber, parallel to the plane of the iris, until reaching thetrabecular meshwork in the opposite angle.

[0078] The surgeon visualizes the trabecular meshwork under directmicroscopy and engages the superficial layers of the meshwork at themidpoint of the trabecular band. The incision is typically made 100° to120°, as designated by αin FIG. 4b, circumferentially, first incisingclockwise 5020 to 60°, then counterclockwise for 50° to 60°.

[0079] As the tissue is incised, a white line can be seen and the irisusually drops posteriorly. An assistant facilitates incision by rotatingthe eye in the opposite direction of the action of the blade (FIG. 4c).

[0080] The surgeon completes the goniotomy incision and promptlywithdraws the blade. If aqueous escapes from the wound and the chamberis shallow, the surgeon can slide the goniotomy lens over the incisionas the blade is withdrawn. The anterior chamber can be reformed with aninjection of balanced salt solution through the external edge of thecorneal incision. The leak can be stopped using a suture and burying theknot.

[0081] Trabeculodialysis

[0082] Trabeculodialysis is similar to goniotomy but is performedprimarily in young patients with glaucoma secondary to inflammation.Trabeculodialysis differs from goniotomy only in the position of theincision. FIGS. 5a-d show the steps of a trabeculodialysis procedure.The knife 500 passes across the anterior chamber and engages thetrabecular meshwork at Schwalbe's line rather than at the midline of themeshwork, as shown in FIG. 5a.

[0083] The incision is typically made 100° to 120° circumferentially, asdesignated by α in FIG. 5b, first incising clockwise 50° to 60°, thencounterclockwise for 50° to 60° (FIG. 5b).

[0084] With the flat side of the blade, the surgeon pushes thetrabecular meshwork inferiorly toward the surface of the iris, as shownin FIG. 5c. FIG. 6d shows the meshwork, disinserted from the scleralsulcus, exposing the outer wall of Schlemm's canal.

[0085] Trabeculotomy

[0086] Trabeculotomy displaces trabecular meshwork as a barrier toaqueous outflow. Initially, the surgeon creates a triangular scleralflap 604 that is dissected anteriorly of the limbus, as shown in FIG.6a. A radial incision is made over the anticipated site of Schlemm'scanal (FIG. 6a). The incision is deepened until the roof of Schlemm'scanal is opened (FIG. 6c).

[0087] The surgeon locates Schlemm's canal through the external surfaceof the limbus, threads a trabeculotome 600 into the canal and rotatesthe instrument into the anterior chamber, as shown in FIG. 6d. The upperarm 610 of the instrument should be kept parallel to the plane of theiris. The instrument 600 is then rotated within the anterior chamber andmaintained parallel to the iris. After rotating the instrument 600through the meshwork in one direction, the surgeon withdraws theinstrument and inserts a second instrument with the opposite curve. Theidentical procedure is then performed in the opposite direction.

[0088] Collapse of the anterior chamber often occurs during theprocedure. The chamber can be reformed by injecting irrigation fluid.Aspiration may be used to remove the tissue. The scleral flap 604 maythen be sutured closed, as shown in FIG. 6e.

[0089] Goniectomy Cauterization Probe

[0090] A preferred embodiment of a goniectomy probe, used to cauterizeand ablate the trabecular meshwork is shown in FIGS. 7 and 8. The probe700 comprises a handle 705 and a probe tip 710. Preferably, the handleis approximately 20 gauge and the probe tip is approximately 27 gauge.The proximal end of the handle is adapted for mating with a connector712 to the output terminals of an energy source 760.

[0091] The probe also includes electrical leads 834 (FIG. 8), a powercable 708, preferably a coaxial cable, and actuation means. Thesecomponents extend from the handle 705, through an electrical lead lumen832 (FIG. 8) in the probe shaft 705, to the corresponding components ofthe probe 700 disposed on the distal end. The proximal ends of thecables and lumens connect to the corresponding connectors that extendfrom the distal end of the probe handle 705.

[0092] Aspiration and irrigation may be provided by an aspiration pump770 and irrigation pump 780. The aspiration pump 770 is connected to astandard vacuum supply line to promote the withdrawal of the aspirationfluid. Aspiration vacuum control may be provided by an aspiration valve.In a preferred embodiment, as shown in FIG. 8, both irrigation andaspiration may be provided by the same lumen 822, alternating the pumpas needed. However, the irrigation lumen 922 and aspiration lumen 924are separate in the embodiment of FIG. 9, providing for simultaneousirrigation and aspiration. Irrigation under pressure flushes blood fromthe eye and expands the anterior chamber, providing more room for theprocedure.

[0093] The handle 705 may be made of an electrically insulatingpolymeric material, configured in a pencil-shape form having acylindrical body region 702 and a tapered forward region 704. Acontoured handle helps to reduce the holding force required and increaseproprioceptive sensitivity. Although a pencil-shape configuration ispreferred, it is noted that any configuration of the handle 705 which iseasily, comfortably and conveniently grasped by the operator will alsobe suitable and is considered to be within the scope of the presentinvention.

[0094] The probe tip 710 is connected to the main body of the handle705. The probe tip further comprises a footplate 721, which protects thecollector channels, penetrates the trabecular meshwork, and serves as aguide in Schlemm's canal. The cautery element 730, located at the distalend of the probe tip 710 may have a variety of configurations.

[0095] The tip 710 may be any material, such as titanium, brass, nickel,aluminum, stainless steel, other types of steels, or alloys.Alternatively, non-metallic substances may also be used, such as certainplastics. The malleable probe tips can be configured as straight, angledor curved, for example, which provides for optimal access to specificanatomy and pathology. Unique tip designs improve tactile feedback foroptimal control and access, and provide for improved tissuevisualization with greatly reduced bubbling or charring.

[0096] The probe tip 710 comprises an electrode 730, suitable forcautery, as known to those of skill in the art. Various electrodeconfigurations and shapes may be suitable. The cautery element 730 maybe any electrode that may provide ablation or cauterization of tissue,such as an ultrasound transducer, a RF electrode, or any other suitableelectrode.

[0097] The cautery element may also include other cautery energy sourcesor sinks, and particularly may include a thermal conductor. Examples ofsuitable thermal conductor arrangements include a metallic element whichmay, for example, be constructed as previously described. However, inthe thermal conductor embodiment such a metallic element would begenerally resistively heated in a closed loop circuit internal to theprobe, or conductively heated by a heat source coupled to the thermalconductor.

[0098] The probe tip may have a coating such as a non-stick plastic or acoating comprising diamond to prevent undesirable sticking or charringof tissue. The electrode may be provided on the inner surface of thetip. Alternatively, the electrode is embedded in a sheath of a tube.Insulation is provided around the cautery element so that other areas ofthe eye are not affected by the cauterization. A sleeve shield or anon-conductive layer may be provided on the probe tip to expose only aselected portion of the electrode. The sleeve preferably has sufficientthickness to prevent both current flow and capacitance coupling with thetissue.

[0099] The electrode or other device used to deliver energy can be madeof a number of different materials including, but not limited tostainless steel, platinum, other noble metals, and the like. Theelectrode can also be made of a memory metal, such as nickel titanium.The electrode can also be made of composite construction, wherebydifferent sections are constructed from different materials.

[0100] In a preferred embodiment, the probe assembly is bipolar. In abipolar system, two electrodes of reversed polarity are located on theprobe tip, thus eliminating the contact plate for completion of thecircuit. Additionally, any number of pairs of electrodes may be providedon the probe tip.

[0101] In an alternative embodiment, the probe assembly is monopolar. Ina monopolar system, the system comprises a single electrode and acontact plate is attached to the surface of the human body. The contactplate is further connected to the minus terminal of the power source viaa lead wire. Voltages of reversed polarity are applied to the electrodeand the contact plate.

[0102] In a preferred embodiment as shown in FIGS. 10a and 10 b, anelectrode assembly of a bipolar probe includes one electrode 1020 madefrom a stainless steel 20 gauge hollow needle and a second electrode1030 formed as a layer of electrically conductive material (such assilver or nickel) deposited over and adhered on an exterior surface ofthe needle electrode 1020. A thin electrical insulator 1028 separatesthe electrodes 1020, 1030, along their lengths to avoid shortcircuiting.

[0103] The electrode 1020 extends along a longitudinal axis 1072 of thefootplate 721 (FIG. 7) from a proximal region at which bipolarelectrical power is applied to a distal region of the electrodeassembly.

[0104] In a preferred embodiment, the second electrode 1030 extends overa limited portion of the circumference of the first electrode 1020,rather than entirely around the first electrode. Current flows over arelatively small portion of the circumference and length of the firstelectrode 1020. This limits the area in the body that receives current,and provides the operator with a high degree of control as to where thecurrent is applied. The second electrode 1030 extends over an arc ofapproximately one quarter of the circumference of the first electrode1020. The second electrode 1030 is disposed symmetrically about an axis1072.

[0105] In a preferred embodiment, the first electrode, and thus thefootplate 721, has a central passage 1022 that is open at the distalregion, providing for irrigation and aspiration. The irrigation andaspiration lumens extend from the distal end of the probe tip 1010,through the probe handle, to the connector, providing for irrigation andaspiration capability.

[0106] In an embodiment as shown in FIGS. 11a and 11 b, the electrodeassembly includes a central or axial electrode 1120 formed by a solidcylindrical metal member, and an elongate hollow outer electrode 1130formed by a cylindrical metal tube member, which is coaxially positionedaround the central electrode 1120. The cylindrical outer surface ofelectrode 1130 forms the circumferential surface of the probe. The outerelectrode 1130 is preferably made of stainless steel or other corrosiveresistant, conductive material for strength as well as conductivity. Theinner electrode 1120 may be made of copper, but less conductivematerials may also be employed. The coaxial relationship and spacingbetween the electrodes 1120, 1130, as well as their electrical isolationfrom one another, is provided by a tubular sleeve 1128 of anelectrically insulating material between the electrode.

[0107] A layer of insulation 1132 may also surround the second electrode1130. One or more regions of insulating area 1132 may be removed at anysuitable location along the axis to expose a region of electrode 1130.Cauterization would occur at the exposed region. The circumferentialextent of the second electrode 1130 can be further limited, depending onthe degree of control desired over the size of the area to which currentis applied.

[0108] In an alternative embodiment, as shown in FIG. 12, the activeregion at a remote end of a bipolar electrode is formed by a hollowmetal tube 1200 having a substantially cylindrical layer of insulation1228 on the outer surface of the metal tube. The metallic tube 1200 isnot an electrode and is provided only for the strength of the probeassembly. The tip supports two metal electrodes 1230, 1240. Each of theelectrodes 1230, 1240 have electric leads, which extend through thehollow interior of the tube 1200 to a supporting insulative handle whereit is coupled by appropriate means with a power source in the mannerpreviously described. Energy flows between the electrodes 1230, 1240,heating only the tissue adjacent the gap therebetween. Aspiration andirrigation may be provided through a lumen 1222.

[0109]FIGS. 13 and 14 show alternative embodiments of a goniectomycauterization probe 1300, 1400. The probe comprises a handle 1305, 1405and a probe tip 1310, 1410. The probe tip includes a cautery element1330, 1430.

[0110] The probes 1300, 1400 are provided with an energy source;however, probe 1400 also includes an irrigation supply 1480 and anaspiration pump 1470. These components connect to the probe 1300, 1400at connector 1308, 1408.

[0111]FIGS. 15a, b show detailed views of probe tip 1310. The probe tip1510 is straight and includes an electrode 1530 attached to electrode1520, which are separated by a layer of insulation 1528.

[0112]FIGS. 16a, b show detailed views of probe tip 1410. The probe tip1610 is straight and includes an electrode 1630 attached to a hollowelectrode 1620, which are separated by a layer of insulation 1628. Thehollow electrode 1620 forms a hollow passage 1622 for irrigation andaspiration.

[0113] In an alternative embodiment, the needle tip of FIG. 14 maycomprise a hollow needle, with or without a cauterizing element,acoustically coupled to an ultrasonic handle and surrounded by a hollowsleeve. The handle includes an ultrasonic transducer, such as that usedfor phacoemulsification, which may be either piezoelectric ormagnetostrictive. When the handle is activated, the needle is vibratedlongitudinally at an ultrasonic rate. Simultaneously, a hydrodynamicflow of irrigation fluid may be introduced into the eye. The vibratingneedle emulsifies the tissue, and the particles are preferablysimultaneously aspirated, along with the fluid, out of the eye throughthe hollow needle tip. Aspiration is effected by a vacuum pump, which isconnected to the handle. The ultrasonically vibrated needle emulsifiesthe tissue by combining i) the mechanical impact of the needle tip whichvaries depending on its mass, sharpness, and acceleration, ii) theultrasonic acoustical waves generated by the metal surfaces of thevibrating needle, iii) the fluid wave created at the needle's leadingedge, and iv) implosion of cavitation bubbles created at the tip of thevibrating needle.

[0114] In an alternative embodiment, sonic technology may be used toablate the tissue. Sonic technology offers an innovative means ofremoving material without the generation of heat or cavitational energyby using sonic rather than ultrasonic technology. The tip expands andcontracts, generating heat, due to intermolecular frictional forces atthe tip, that can be conducted to the surrounding tissues. The tip doesnot need a hollow sleeve if sonic energy is used to remove thetrabecular meshwork.

[0115] The use of acoustic energy, and particularly ultrasonic energy,offers the advantage of simultaneously applying a dose of energysufficient to ablate the area without exposing the eye to current. Theultrasonic driver can also modulate the driving frequencies and/or varypower in order to smooth or unify the produced collimated ultrasonicbeam.

[0116] The amount of heat generated is directly proportional to theoperating frequency. The sonic tip does not generate cavitationaleffects and thus true fragmentation, rather than emulsification orvaporization, of the tissue takes place. This adds more precision andpredictability in cutting and less likelihood of damage to other areasof the eye. The tip can be utilized for both sonic and ultrasonic modes.The surgeon can alternate between the two modes using a toggle switch ona foot pedal when more or less energy is required.

[0117]FIG. 17 shows the control system for a goniectomy cauterizationprobe. The cautery element 1730 is coupled to a cautery actuator. Thecautery actuator generally includes a radio-frequency ( “RF”) currentsource 1760 that is coupled to both the RF electrode and also a groundpatch 1750 which is in skin contact with the patient to complete an RFcircuit, in the case of a monopolar system. The cautery actuator mayinclude a monitoring circuit 1744 and a control circuit 1746 whichtogether use either the electrical parameters of the RF circuit ortissue parameters such as temperature in a feedback control loop todrive current through the electrode element during cauterization. Also,where a plurality of cautery elements or electrodes are used, switchingcapability may be provided to multiplex the RF current source betweenthe various elements or electrodes.

[0118] The probe is connected to a low voltage power source via a powercord that mates with the handle. The source may be a high frequency,bipolar power supply, preferably, a solid state unit having a bipolaroutput continuously adjustable between minimum and maximum powersettings. The source is activated by an on/off switch, which maycomprise a foot pedal, or a button on the probe or interface. The sourceprovides a relatively low bipolar output voltage. A low voltage sourceis preferred to avoid arcing between the electrode tips, which coulddamage the eye tissue. The generator is coupled to first and secondelectrodes to apply a biologically safe voltage to the surgical site.

[0119] Delivery of energy to the tissue is commenced once the cauteryelement is positioned at the desired location. The energy sourcepreferably provides RF energy, but is not limited to RF and can includemicrowave, ultrasonic, coherent and incoherent light thermal transferand resistance heating or other forms of energy as known to those ofskill in the art. Energy is typically delivered to the cautery elementvia electrical conductor leads. The cautery control system may include acurrent source for supplying current to the cautery element.

[0120] The current source is coupled to the cautery element via a leadset (and to a ground patch in some modes). The monitor circuit 1744desirably communicates with one or more sensors (e.g., temperature) 1730which monitor the operation of the cautery element. The control circuit1746 may be connected to the monitoring circuit 1744 and to the currentsource 1760 in order to adjust the output level of the current drivingthe cautery element based upon the sensed condition (e.g. upon therelationship between the monitored temperature and a predeterminedtemperature set point).

[0121] The procedure for performing goniectomy with the goniectomycauterization probe of an embodiment of the present invention is similarto a traditional goniotomy surgery, as previously described. The surgeonpreferably sits on the temporal side of the operating room tableutilizing an operating microscope. The patient's head is rotated 45°away from the surgeon after a retrobulbar injection has anesthetized theeye. A knife, preferably 20 gauge, is used to make a clear cornealtemporal incision. The goniectomy instrument is inserted into theanterior chamber up to the infusion sleeve to maintain the intraocularpressure and deepen the anterior chamber. The surgeon positions thegonio lens, preferably a Schwann-Jacobs lens or a modified Barkangoniotomy lens, on the cornea. The goniectomy probe is advanced to thetrabecular meshwork. The sharp end point of the footplate incises themiddle one third of the trabecular meshwork, which is known as thepigmented portion of the trabecular meshwork. The footplate 721 (FIG. 7)is further inserted into Schlemm's canal. The cautery element isactivated, preferably by a footplate, which may also be used to activateirrigation and aspiration. The current provided to the cautery elementheats the tissue. The instrument is slowly advanced through thetrabecular meshwork maintaining the footplate 721 in Schlemm's canal,feeding the pigmented trabecular meshwork into the opening of theinstrument where the tissue removal occurs. The instrument is advanceduntil no further tissue can be removed inferiorly. The tissue may alsobe aspirated through the probe, thus substantially removing a portion ofthe trabecular meshwork. The instrument may be rotated in the eye andreintroduced into Schlemm's canal where the initial incision began. Thesuperior portion of the trabecular meshwork is then removed usingcautery and aspiration. In a preferred embodiment, a substantialportion, preferably at least half, of the trabecular meshwork isremoved. The corneal incision is preferably sealed by injecting abalanced salt solution into the corneal stroma or by placing a suture.The anterior chamber is reformed. A visceolastic substance may beutilized to maintain the anterior chamber with the initial incision andat the end of the surgery.

[0122] Trabeculodialysis

[0123] Trabeculodialysis is similar to goniectomy; therefore, agoniectomy cauterization probe may also be used to performtrabeculodialysis. The procedure for performing a trabeculodialysisprocedure with a cauterization probe is similar to the trabeculodialysisprocedure previously described. However, rather than cutting the tissuewith a knife, the tissue is ablated with the probe. Similarly, in apreferred embodiment, a substantial portion, preferably at least half,of the trabecular meshwork is removed.

[0124] Goniectomy Cutting Probe

[0125] Another preferred embodiment of a goniectomy cutting probe, usedto cut and remove trabecular meshwork, is shown in FIG. 18. The probecomprises a handle 1805 and a probe tip 1810. Preferably, the handle is20 gauge and the probe tip is approximately 25 gauge. The handle 2405 issized and configured to fit completely and comfortably within a hand.The handle 2405 may be formed of a variety of materials, includingplastics, and may be designed in a variety of shapes. Generally, it willbe preferred that a convenient shape for gripping, such as a cylindricalshape, be provided. The probe tip 1810 further comprises a footplate1820, protecting endothelial cells and collector channels lining thescleral wall of Schlemm's canal. The footplate 1820 also serves as aguide in Schlemm's canal. The sharpened end of the footplate is used topenetrate the trabecular meshwork.

[0126] FIGS. 19-20 show sectional views of different embodiments of theinternal components and construction of the probe 1800. The probe isconfigured to define therewithin a hollow inner chamber. A drive member,coupled to a rotatable drive cable within a drive cable assembly, extendinto the hollow inner chamber, as shown. A rotatable drive shaft 1944,2044 is rotatably connected or engaged to the drive member, such thatthe shaft may be rotatably driven at speeds required for the trabecularmeshwork removal. The rotatable drive shaft is inserted into a boreformed in the distal face of the drive member.

[0127] The elongate rotatable drive shaft 1944, 2044 passeslongitudinally through the probe and terminates, at its distal end, in acutting head 1945, 2045. A protective tubular sheath may be disposedabout the rotatable shaft. The rotatable shaft and/or sheath are axiallymovable so as to allow the cutting head to be alternately deployed in a)a first non-operative position wherein the cutting head is fully locatedwithin the inner bore of the tubular sheath so as to be shielded duringinsertion and retraction of the instrument or b) a second operativeposition wherein the cutting head is advanced out of the distal end ofthe sheath so as to contact and remove the trabecular meshwork. Thecutting head 1945, 2045 may be configured such that rotation of the headwill create and sustain a forced circulation of fluid within themeshwork. Such forced circulation causes the trabecular meshwork to bepulled or drawn into contact with the rotating cutting head, without theneed for significant axial movement or manipulation of the probe whilethe cutting head is rotating.

[0128] A control pedal may be connected to the motor-drive system toinduce actuation/deactuation, and speed control of the rotatable drivecable within the drive cable assembly by the operator. Additionalswitches or control pedals may be provided for triggering and actuatingirrigation and/or aspiration of fluid and/or debris through the probe.

[0129] The probe of FIG. 19, shows the probe 1900 having two separatelumens, 1922, 1924, for irrigation and aspiration. The hollow passageway2022 extending longitudinally through the probe of FIG. 20, containingthe rotatable drive shaft, is in fluid communication with an irrigationpump (not shown). By such arrangement, a flow of irrigation fluid may beinfused through the tube. A separate lumen 2024 is also provided foraspiration.

[0130] The independent processes of irrigation and aspiration may beperformed simultaneously with the rotation of the head or while the headis in a non-rotating, stationary mode. It will also be appreciated thatthe infusion and aspiration pathways may be reversed or interchanged byalternately connecting the aspiration pump to the irrigation tubing andirrigation pump to the aspiration tubing.

[0131] In an alternative embodiment, as shown in FIGS. 21-23, the probecuts tissue in a guillotine fashion. As shown in FIG. 21, the probe 2100may include an inner sleeve 2144 that moves relative to an outer sleeve2146. The sleeves are coupled to the handle. The inner sleeve 2144 maybe coupled to a vacuum system which pulls tissue into the port 2125 whenthe inner sleeve 2144 moves away from the port. The inner sleeve 2144then moves in a reverse direction past the outer port to sever tissue ina guillotine fashion. The vacuum system draws the severed tissue awayfrom the port, so the process may be repeated. The inner sleeve may beconnected to a diaphragm and a spring, rigidly attached to the handle.The diaphragm is adjacent to a pneumatic drive chamber that is in fluidcommunication with a source of pressurized air (not shown). The drivechamber is pressurized, expanding the diaphragm. Expansion of thediaphragm moves the inner sleeve so that the tissue within the port issevered by the sleeve. Alternatively, the inner sleeve 2144 is driven bya motor located within the handle. The inner sleeve 2144 is coupled tothe motor by a rotating lever mechanism or wobble plate, inducing anoscillating translational movement of the sleeve in response to arotation of the output shaft. The motor is preferably an electricaldevice coupled to an external power source by wires that are attached toa control system at the handle.

[0132]FIG. 22 shows an embodiment wherein the irrigation lumen 2222contains the cutting sleeve 2244. Cutting sleeve 2244 has a cuttingblade 2245 integrally formed at its distal end. FIG. 23 shows analternative embodiment, wherein the irrigation lumen 2322 does notcontain the cutting sleeve. An aspiration lumen 2224, 2324 is alsoprovided. The aspiration line may be directly coupled to an aspirationpump; the irrigation lumen may be directly coupled to an irrigationpump.

[0133] The procedure for goniectomy with the goniectomy cutting probe issimilar to the goniectomy procedure discussed for the goniectomycauterization probe. However, rather than cauterizing the trabecularmeshwork, the tissue is cut using a rotatable blade or cut in aguillotine fashion, and subsequently aspirated. In a preferredembodiment, a substantial portion, preferably at least half, of thetrabecular meshwork is removed.

[0134] Goniectomy Laser Probe

[0135] A laser probe 2400, as shown in FIGS. 24a and 24 b, is providedto ablate the trabecular meshwork. The probe 2400 comprises a handle2405 and a probe tip 2410. The handle 2405 is sized and configured tofit completely and comfortably within a hand. It will be understood thatthe handle 2405 may be formed from a variety of materials, includingplastics, and may be designed in a variety of shapes. Generally, it willbe preferred that a convenient shape for gripping, such as a cylindricalshape, be provided. The main body of the handle 2405 comprises a plastichousing within which a laser system is contained. The plastic housing isprovided to enable easy manipulation of the handle 2405 by the user. Thelaser is preferably an excimer laser.

[0136]FIG. 24a shows an embodiment wherein the laser source is containedwithin the probe, but rather within the control system. A fiber isprovided to direct the light energy from the source to the proximal endof the probe tip. The laser radiation is generated in close proximity tothe eye, so that relatively little laser light is lost duringtransmission.

[0137]FIG. 24b shows an embodiment wherein the laser source is notcontained within the probe. The source may include a longitudinalflashlamp. A fiber is provided to direct the light energy from thesource to the proximal end of the probe tip.

[0138] The probe tip 2410 is connected to the main body 2405. The probetip comprises a footplate to protect the outer wall of Schlemm's canal,such that only the tissue of the trabecular meshwork is cauterized. Thefootplate also is used to penetrate the trabecular meshwork and servesas a guide in Schlemm's canal. In general, the probe tip 2410 isstraight or curved.

[0139]FIG. 25 shows a detailed view of FIG. 24a. The handle includes areflective tube 2508 which has a mirrored inside surface. An Er: YAG rod2513 is located along the axis of the tube 2508. The pump for the laserlight source is preferably a high pressure flashtube 2512 or a similarsuitable light source which is located adjacent the rod 2513 within thereflective tube 2508. The flashtube 2512 produces very brief, intenseflashes of light, there being approximately 10 to 100 pulses per second.

[0140] Er:YAG rods generate an output wavelength of approximately 2.94microns. Use of an erbium doped laser, such as an Er: YAG laser, isadvantageous because it requires less power to ablate the eye tissuethan do the Nd: YAG and Holmium:YAG lasers of the prior art. Preferablythe Er: YAG laser has a pulse repetition rate of 5 to 100 Hz, a pulseduration of 250 μs to 300 μs, and a pulse energy of 10 to 14 mJ perpulse. Using an Er: YAG laser at the above parameters limits the thermaldamage of surrounding tissue to a depth of 5 to 50 microns. By reducingthe thermal damage of surrounding tissue, the amount of scar tissuebuildup caused by the laser is minimal. Thus, the likelihood that thepassageway will become blocked with scar tissue is reduced, and thelikelihood that the procedure will need to be repeated is reduced.

[0141] The reflective inner surface 2546 of the tube 2508 serves toreflect light from the flashlamp 2512 to the rod 2513. Reflection of thelight by the cylindrical mirror focuses as much light as possible towardthe rod 2513. This results in efficient coupling between the lightsource 2512 and the laser rod 2513. Thus, essentially all lightgenerated in the flashtube 2512 is absorbed by the laser rod 2513.

[0142] The rod 2513 has a totally reflective mirror 2514 and outputmirror 2517 at its two ends. The mirror 2514 at the proximal end of therod 2513 provides 100% reflection of light back to the rod 2513. At theremote end of the rod 2513, the output mirror 2517 provides less than100% reflection. Thus, while most of the light energy directed towardthe output mirror 2517 of the rod 2513 is reflected back into the rod2513, intensifying the beam, some of the waves of energy pass throughthe output mirror 2517 and into the transmission system 2511 forconducting it toward the probe tip 2515. A reflective coating on the endof the laser rod 2513 may be used to supplement or replace the mirrors2517, 2514.

[0143] The mirrors 2517, 2514 on either end of the rod form a resonator.Radiation that is directed straight along the axis of the rod 2513bounces back and forth between the mirrors 2517, 2514 and builds astrong oscillation. Radiation is coupled out through the partiallytransparent mirror 2517.

[0144] The transmission system 251 is preferably an optical fiber.Preferably, a sapphire or fused silica fiber will be used with thelaser, contained within the handle. A germanium oxide Type IV fiber isalso suitable for carrying erbium laser light with reduced attenuation.It is also possible to deliver laser light through hollow waveguides.Such waveguides often include multi-layer dielectric coatings to enhancetransmission.

[0145]FIG. 26 shows a detailed view of one embodiment of a probe tip2600, in which the fiber 2610 is centrally located within the probe tip2600.

[0146] Alternatively, the probe tip may be hollow, forming anaspiration/irrigation lumen (not shown). The lumen extends the entirelength of the probe. Alternatively, as shown in FIG. 27, the lumen 2722may extend adjacent the probe tip 2710. The aspiration lumen 2722communicates with a vacuum source for withdrawal of emulsified materialthrough an aperture or aspiration port. During use, the vacuum sourcecan be employed to aspirate material which has been fragmented orablated by the pulsed laser light. The vacuum source can also be used todraw the tissue into close proximity with the delivery end of the probethereby facilitating its destruction. Fluid introduced through thelumen, chamber, and aperture can provide for flushing of the site andreplacement of lost volume due to removal of the emulsified material.

[0147] The probe is inserted under direct vision to ablate thetrabecular meshwork for use in treating glaucoma, thus obtaining a freeflow of aqueous from the anterior chamber into Schlemm's canal andthrough the collector channels. The end of the probe is inserted througha relatively small incision in the eye, and can be maneuvered very closeto the tissue to be emulsified.

[0148] The procedure is similar to the goniectomy procedure previouslydiscussed with reference to the goniectomy cauterization probe. Thesurgeon visualizes the trabecular meshwork under direct microscopy andengages the superficial layers of the meshwork at the midpoint of thetrabecular band, by placing the tissue between the end 2521 of the fiber2511 and the probe tip (footplate) 2519. Once inserted, the fiber 2511is positioned to focus laser energy directly on the trabecular meshwork.The probe tip 2519 absorbs any laser energy which is not absorbed by thetrabecular meshwork, thus protecting Schlemm's canal from damage. Lightis transmitted to and through the probe, and the tissue is ablated. Thearea may be irrigated and aspirated, removing the tissue from the eye.In a preferred embodiment, a substantial portion, preferably at leasthalf, of the trabecular meshwork is removed. After treatment, the probeis readily withdrawn from the eye. Leakage may be stopped using a sutureand burying the knot.

[0149] Laser treatment with an Er:YAG laser is advantageous because aswavelength increases, contiguous thermal effects decrease. In thevisible portion of the spectrum, water has minimal absorption. Above 2.1μm however, this absorption increases to a level comparable to excimerlasers operating around 200 nm. This increase is quite rapid. A markeddifference therefore exists between radiation at 2.79 μm and 2.94μm.This confines the energy delivered to a smaller volume, allowing moreablation to occur at lower total energy levels and limiting contiguousthermal damage. Er: YAG lasers produce ablations with minimal amounts ofcontiguous thermal damage. Light in the infrared region has anadditional advantage over ultraviolet radiation in that it is not knownto have mutagenic or carcinogenic potential.

[0150] Due to the large absorption band of the water at the wavelengthof the erbium laser, no formation of sticky material on the probe tiptakes place, which can be a serious problem at other wavelengths.

[0151] Schlemmectomy Cauterization Probe

[0152] Schlemmectomy is a new surgical procedure, similar totrabeculotomy. However, in a schlemmectomy procedure, disrupted tissueis removed using a schlemmectomy cauterization probe. FIG. 28illustrates a probe 2800 in accordance with this invention for removalof the trabecular meshwork, using a cautery element 2830 on a probesimilar to a traditional trabeculotome, such as Harm's trabeculotome.The probe uses both cautery and mechanical disruption to ablate thefibers of the trabecular meshwork, leaving a patent open Schlemm'scanal.

[0153] The probe 2800 comprises a handle 2805 and a probe tip 2810. Theproximal end of the handle is adapted for mating with a connector 2812to the output terminals of an energy source 2860.

[0154] The probe also includes electrical leads 2934 (FIG. 29), a powercable 2808, preferably a coaxial cable, and an actuator. Thesecomponents extend from the handle 2805, through an electrical lead lumen2932 (FIG. 29) in the probe shaft 2805, to the corresponding componentsof the probe 2800 disposed on the distal end. The proximal ends of thecables and lumens connect to the corresponding connectors that extendfrom the distal end of the probe handle 2805.

[0155]FIGS. 29a-c illustrate one probe tip configuration. The probe tip2910 comprises two parallel arms 2920, 2950. The probe tip 2910comprises an electrode 2930, which will be described in further detailbelow, disposed on the lower arm 2920. The probe tip 2910 comprises anelectrical lead lumen 2932 which extends the length of the probe tip2910 from the electrode 2930 through the cylindrical body 2802 to theconnector of the probe handle 2812. (FIG. 28)

[0156]FIG. 30 shows a preferred embodiment of a probe 3000. The probe ofFIG. 30 is similar to the probe of FIG. 28, except that probe 3000further comprises irrigation means. Irrigation may be provided by anirrigation pump 3080 or hydrostatic pressure from a balanced saltsolution bottle and tubing.

[0157] In a preferred embodiment, as shown in FIG. 31a, the irrigationlumen 3122 is situated at the end of the probe. Irrigation underpressure flushes blood from the eye and expands Schlemm's canal and theanterior chamber, providing more room for the procedure. Alternatively,lumen 3122 provides for aspiration by connecting the lumen to anaspiration pump. Aspiration ports may be provided equidistantly alongthe length of the cauterizing element of the trabeculotome, as shown inFIG. 31b. In an embodiment, as shown in FIG. 31c, two lumens areprovided, an irrigation lumen 3122 and an aspiration lumen 3124. Twoseparate lumens provide for simultaneous irrigation and aspiration.

[0158] With reference to the schlemmectomy probes of FIGS. 28 and 30,the handle 2805, 3005 may be made of an electrically insulatingpolymeric material, configured in a pencil-shape form having acylindrical body region 2802, 3002 and a tapered forward region 2804,3004. Although a pencil-shape configuration is preferred, it is notedthat any configuration of the handle 2805, 3005 which is easily,comfortably and conveniently grasped by the operator will also besuitable and is considered to be within the scope of the presentinvention.

[0159] The probe tip 2810, 3010 is connected to the main body of thehandle 2805, 3005. The cautery element 2830, 3030 at the distal end ofthe probe tip 2810, 3010 can have a variety of configurations.

[0160] The tip 2810, 3010 may be any material, such as titanium, brass,nickel, aluminum, stainless steel, other types of steels, or alloys.Alternatively, non-metallic substances may also be used, such as certainplastics. The tip may be conductive or nonconductive, depending on thespecific embodiment, as will be discussed.

[0161]FIGS. 32a and 32 b show alternative distal probe tipconfigurations, wherein the second electrode 3230 extends along theentire length of the first electrode 3220. The probe tip 3210 may becurved to better maneuver within the anatomy of the eye. The malleableprobe tips can be configured as straight, angled or curved, for example,which provides for optimal access to specific anatomy and pathology.Unique tip designs improve tactile feedback for optimal control andaccess, and provide for improved tissue visualization with greatlyreduced bubbling or charring.

[0162] Referring again to the probes of FIGS. 28 and 30, the probe tip2810, 3010 comprises an electrode or cautery element 2830, 3030,suitable for cautery, as known to those of skill in the art. Variouselectrode configurations and shapes may be suitable. The cautery element2830, 3030 is any electrode that may provide ablation or cauterizationof tissue, such as a RF electrode, an ultrasound transducer, or anyother suitable electrode. Alternatively, or in addition to the RFelectrode variations, the cautery element may also include other cauteryenergy sources or sinks, and particularly may include a thermalconductor. Examples of suitable thermal conductor arrangements include ametallic element which may, for example, be constructed as previouslydescribed. In the thermal conductor embodiment such a metallic elementwould be generally resistively heated in a closed loop circuit internalto the probe, or conductively heated by a heat source coupled to thethermal conductor.

[0163] The electrode 2830, 3030 may be provided on the inner surface ofthe tip. Alternatively, the electrode 2830, 3030 may be embedded in asheath of a tube. Insulation may be provided around the cautery elementso that other areas of the eye are not affected by the cauterization. Asleeve shield or a non-conductive layer may also be provided on theprobe tip to expose only a selected portion of the electrode. The sleevepreferably has sufficient thickness to prevent both current flow andcapacitance coupling with the tissue.

[0164] The cautery element can be made of a number of differentmaterials including, but not limited to stainless steel, platinum, othernoble metals, and the like. The electrode can also be made of a memorymetal, such as nickel titanium. The electrode can also be made ofcomposite construction, whereby different sections are constructed fromdifferent materials.

[0165] In a preferred embodiment of an RF electrode, the electrodesystem is bipolar. In a bipolar system, two electrodes of reversedpolarity are located on the probe tip and RF energy bridges theelectrodes. Additionally, any number of pairs of electrodes may beprovided on the probe tip.

[0166] In an alternative RF electrode embodiment, the electrode systemis monopolar. In a monopolar system, the system comprises a singleelectrode and a contact plate. The contact plate is attached to thesurface of the human body. The contact plate is further connected to thereturn terminal of the power source via a lead wire. Voltages of reversepolarity are applied to the electrode and the contact plate.

[0167] In a preferred embodiment, as shown in FIGS. 33a and 33 b, anelectrode assembly of a bipolar probe includes one electrode 3320 madefrom a stainless steel 20 gauge hollow needle and a second electrode3330 formed as a layer of electrically conductive material (such assilver or nickel) deposited over and adhered to an exterior surface ofthe needle electrode. A thin electrical insulator 3324 separates theelectrodes 3320, 3330, along their lengths to avoid short circuiting.

[0168] The electrodes 3320, 3330 extend along a longitudinal axis 3372of the instrument from a proximal region at which bipolar electricalpower is applied to a distal region of the electrode assembly.

[0169] In a preferred embodiment, the second electrode 3330 extends overa limited portion of the circumference of the first electrode 3320,rather than entirely around the first electrode 3320. Current flows fromthe relatively small portion of the circumference of the secondelectrode 3330 where heat is generated in the adjacent tissue, and intothe layer surface of the first electrode 3320, where little heat isgenerated. This limits the area in the body that receives dense current,and provides the operator with a high degree of control as to where thecurrent is applied. The second electrode 3330 extends over an arc ofapproximately one quarter of the circumference of the first electrode.The second electrode 3330 is disposed symmetrically about an axis 3372.

[0170] In a preferred embodiment, the first electrode 3320 has a centralpassage 3322 that is open at the distal region, providing forirrigation. The irrigation lumen 3322 extends from the distal end of theprobe tip, through the probe handle, to the connector, providing forirrigation capability.

[0171]FIG. 34 shows an alternative embodiment, wherein the electrodeassembly includes a central or axial electrode 3420 formed by a solidcylindrical metal member, and an elongate hollow outer electrode 3430formed by a cylindrical metal tube member, which is coaxially positionedaround the central electrode. The cylindrical outer surface of electrode3430 forms the circumferential surface of the probe. The outer electrode3430 is preferably made of stainless steel or other corrosive resistant,conductive material for strength as well as conductivity. The innerelectrode 3420 may be made of copper, but less conductive materials mayalso be employed. The coaxial relationship and spacing between theelectrodes, as well as their electrical isolation from one another, isprovided by a tubular sleeve 3424 of an electrically insulating materialbetween the electrode, completing the probe assembly. An additionallayer of insulation 3434 may be provided on outer electrode 3430 toexpose only a limited portion of the electrode to concentrate RF energyat the limited exposed region.

[0172] Alternatively, one or more regions of insulating area 3434 may beremoved at any suitable location along the axis to expose a region ofelectrode 3430. Cauterization would then occur at the exposed region.The circumferential extent of the second electrode 3430 can be furtherlimited, depending on the degree of control desired over the size of thearea to which current is applied.

[0173] In an alternative embodiment as shown in FIGS. 35a and 35 b, theactive region of a bipolar electrode probe assembly is formed by ahollow metal tube 3515 having a substantially semi-cylindrical sleeve3524 on tube 3515. The metallic tube 3515 is not an electrode and isprovided only for the strength of the probe assembly. The tip supportstwo cautery elements 3520, 3530. Each of the elements 3520, 3530 isconnected to electrical leads, which extend through the hollow interiorof the tip 3510 to a supporting insulative handle where it is coupled byappropriate means with a power source in the manner previouslydescribed.

[0174] The probe is connected to a low voltage RF power source via apower cord that mates with the handle. The source may be a highfrequency, bipolar power supply, preferably, a solid state unit having abipolar output continuously adjustable between minimum and maximum powersettings. The source is activated by an on/off switch, which maycomprise a foot pedal, or a button on the probe or interface. The sourceprovides a relatively low bipolar output voltage. A low voltage sourceis preferred to avoid arcing between the electrode tips, which coulddamage the eye tissue. The RF generator is coupled to first and secondelectrodes to apply a biologically safe voltage to the surgical site.This probe has the advantage of cauterizing at both of the bipolarelements, each of which has a limited, RF current concentration area.

[0175] Delivery of energy to the tissue is commenced once the cauteryelement is positioned at the desired location. Energy is typicallydelivered to the cautery element via electrical conductor leads. Theenergy source preferably provides RF energy, but is not limited to RFand can include microwave, electrical, ultrasonic, coherent andincoherent light thermal transfer and resistance heating or other formsof energy, as known to those of skill in the art.

[0176] The cautery actuator may include a monitoring circuit 1744 and acontrol circuit 1746 (FIG. 17) which together use either the electricalparameters of the RF circuit or tissue parameters such as temperature ina feedback control loop to drive current through the electrode elementduring cauterization. Feedback control systems can be used to obtain thedesired degree of heating by maintaining the selected sight at a desiredtemperature for a desired time. A sensor, such as a thermocouple may beused to monitor temperature in a feedback loop. Where a plurality ofcautery elements or electrodes are used, switching capability may beprovided to multiplex the RF current source between the various elementsor electrodes.

[0177]FIG. 17 shows the monitor circuit 1744, which desirablycommunicates with one or more sensors (e.g., temperature) 1740 whichmonitor the operation of the cautery element 1730. The control circuit1746 may be connected to the monitoring circuit 1744 and to the currentsource in order to adjust the output level of the current driving thecautery element 1730 based upon the sensed condition (e.g. upon therelationship between the monitored temperature and a predeterminedtemperature set point).

[0178] Circuitry, software and feedback to a controller, which result infull process control, may be used to change (i) power—including RF,incoherent light, microwave, ultrasound, and the like, (ii) the dutycycle, (iii) monopolar or bipolar energy delivery, (iv) fluid(electrolyte solution delivery, flow rate and pressure) and (v)determine when ablation is completed through time, temperature and/orimpedance.

[0179] In a preferred embodiment, a bipolar electrode is part of acircuit that includes the RF signal generator, connecting cables, probetip for insertion into the eye, a grounding electrode attached to theprobe and a return cable that connects the grounding electrode to the RFgenerator completing the circuit. Because such a RF electrode is arelatively good conductor, the electrode itself does not heat up. Thetissues that the electrode comes in contact with heat up in response tocurrent passing from the electrode through the tissues. The tissue heatsup because it is a relatively poor conductor as compared to the rest ofthe circuit. It is when the tissues heat up as a result of molecularfriction, that heat is then conducted back to the electrode itself. Atthat point, a thermocouple senses the increase in temperature andsupplies that information to the RF generator so that the feedbackmechanism can attenuate the energy delivered in order to attaintemperature control.

[0180] It may also be advantageous to regulate RF delivery through bothtemperature and impedance monitoring. It may also be advantageous tomonitor irrigation fluid flow to maintain clarity at the site. There isalso an opportunity for synergy between RF and irrigation fluid deliveryto the surgical site to provide, for example, a greater level of controlof temperatures at the site.

[0181] The controller may include an RF generator, temperature profile,temperature regulator, temperature monitor, surgical instrument,impedance monitor, impedance regulator, pump, flow regulator and flowmonitor.

[0182] The RF generator may be capable of delivering monopolar orbipolar power to the probe. The probe is positioned at the surgicalsite. The impedance monitor obtains impedance measurements by, forexample, measuring current and voltage and performing a RMS calculation.The measurements of the impedance monitor are delivered to the impedanceregulator. The impedance regulator performs several functions. Generallythe impedance regulator keeps the impedance levels within acceptablelimits by controlling the power supplied by the RF generator. In oneembodiment of the current invention the impedance regulator can controlthe flow regulator to deliver more or less irrigation fluid to thesurgical site.

[0183] To maintain the appropriate temperature for cauterizing tissue,the distal tip of the probe may also be equipped with a thermocouple1740. Temperature feedback, in combination with a timing device, permitsa precise degree of cautery to be delivered, obtaining the desiredeffect without causing any intraocular heating. The heating effect ontissue may be mitigated with a viscoelastic agent to deepen the anteriorchamber.

[0184] Referring to FIG. 17, the temperature monitor 1744 may includeone or more types of temperature sensors, e.g. thermocouples,thermistors, resistive temperature device (RTD), infrared detectors,etc.

[0185] Suitable shapes for the thermocouple include, but are not limitedto, a loop, an oval loop, a “T” configuration, an “S” configuration, ahook configuration or a spherical ball configuration. These shapesprovide more surface area for the thermocouple without lengthening thethermocouple. These thermocouples, with more exposed area than astraight thermocouple, are believed to have better accuracy and responsetime. The thermocouple is attached by a fastener. The fastener may be abead of adhesive, such as, but not limited to, epoxies, cyanoacetateadhesives, silicone adhesives, flexible adhesives, etc. It may also bedesirable to provide multiple thermocouples at different locations andcompare their operating parameters (e.g. response times, etc.), whichmay provide useful information to allow certain such variables to befiltered and thereby calculate an accurate temperature at thethermocouple location.

[0186] The output of the temperature monitor 1744 is delivered to thetemperature regulator 1746. The temperature regulator 1746 may controlboth the RF generator 1760 and the flow regulator. When, for example,temperatures have increased beyond an acceptable limit, power suppliedby the RF generator to the surgical instrument may be reduced.Alternately, the temperature regulator may cause the flow regulator toincrease irrigation fluid, thereby decreasing the temperature at thesurgical site. Conversely, the temperature regulator can interface witheither the RF generator or the flow regulator when measured temperaturesdo not match the required temperatures. The flow regulator interfaceswith the pump to control the volume of irrigation fluid delivered to thesurgical site.

[0187] The procedure for performing a Schlemmectomy with the probe ofthe present invention is similar to a traditional trabeculotomyprocedure, as previously described. The surgeon preferably sits on thetemporal side of the operating room table utilizing the operatingmicroscope. An infrotemporal fornix based conjunctival flap is made andthe conjunctive and Tenons capsule are mobilized posteriorly. Atriangular flap is made and the superficial flab is mobilized into thecornea. A radial incision is made over the canal of Schlemm, thuscreating an entrance into the canal. Vanna scissors are preferablyintroduced into the Schlemm's canal, opening the canal for approximately1 mm on either side. A clear corneal parenthesis is performed and theanterior chamber is deepened, preferably with Haelon GV. The probe isintroduced into Schlemm's canal inferiorly. The instrument is nowaligned such that the cauterization element faces into the deepenedanterior chamber. Alternatively, the cauterization surface faces thetrabecular meshwork and is activated by the foot switch at the time ofthe rotation of the probe into the anterior chamber. The foot switch maythen be used to activate cauterization. Aspiration and irrigation mayalso be activated using the foot switch. The trabeculotome is slowlyrotated into the anterior chamber and when the blade of thetrabeculotome is seen in the anterior chamber, the cautery (andaspiration and/or irrigation) are deactivated. The superior aspect ofSchlemm's canal may be entered with a trabeculotome having the oppositecurvature. Following the same steps, more of the trabecular meshwork isremoved. In a preferred embodiment, a substantial portion, preferably atleast half, of the trabecular meshwork is removed. After removing thetrabeculotome, the superficial trabeculotomy flap is sutured closedusing sutures.

[0188] Radiowave surgery uses high frequency radio waves instead of heatto cut and coagulate tissue without the burning effect that is commonwith traditional electrosurgical devices and cautery equipment. Theresistance of tissue to the spread of radio wave energy produces heatwithin the cell, causing the water within the cell to volatilize anddestroy the cell without damaging other cellular layers.

[0189] While particular forms of the invention have been described, itwill be apparent that various modifications can be made withoutdeparting from the spirit and scope of the invention. Accordingly, it isnot intended that the invention be limited, except as by the appendedclaims.

What is claimed is:
 1. A probe for the treatment of glaucoma,comprising: a probe tip configured to access the trabecular meshwork; anaspiration port on said probe tip; and a laser providing light energy tosaid probe tip sufficient to ablate said trabecular meshwork.
 2. Theprobe of claim 1, additionally comprising a handle supporting said probetip, and wherein said laser is contained within said handle.
 3. Theprobe of claim 1, further comprising an irrigation port on said probetip.
 4. The probe of claim 3, further comprising a lumen extendingthrough said probe tip and terminating at said irrigation port.
 5. Theprobe of claim 1, further comprising a lumen extending through saidprobe tip and terminating at said aspiration port.
 6. The probe of claim1, further comprising a combined irrigation and aspiration port on saidprobe tip.
 7. The probe of claim 6, further comprising a lumen extendingthrough said probe tip and terminating at said combined irrigation andaspiration port.
 8. The probe of claim 1, further comprising an opticalfiber for conducting said light energy from said laser to said probetip.
 9. The probe of claim 8, wherein said optical fiber is a sapphirefiber.
 10. The probe of claim 8, wherein said optical fiber is a fusedsilica fiber.
 11. The probe of claim 1, additionally comprising a shieldconfigured to protect Schlemm's canal from damage by said laser lightenergy.
 12. The probe of claim 11, wherein said shield and said laserare separated by an opening sufficient to accommodate said trabecularmeshwork.
 13. The probe of claim 11, wherein said shield is sharp enoughto penetrate said trabecular meshwork.
 14. The probe of claim 11 whereinsaid shield is sized to guide said probe tip along Schlemm's canal. 15.The probe of claim 11, wherein said shield extends at a right angle fromsaid probe tip.
 16. The probe of claim 15, wherein said shield lies onthe axis of said laser.
 17. The probe of claim 1, wherein said lasercomprises an Er:YAG laser.
 18. The probe of claim 1 wherein said probetip is configured for goniectomy.
 19. A probe for the treatment ofglaucoma, comprising: a probe tip configured to access the trabecularmeshwork; an aspiration port on said probe tip; and a tissue ablatordisposed on said probe tip and configured to ablate said trabecularmeshwork.
 20. The probe of claim 19 wherein said probe tip is configuredfor schlemmectomy.
 21. The probe of claim 19 wherein said probe tip isconfigured for goniectomy.
 22. The probe of claim 19, further comprisingan irrigation port on said probe tip.
 23. The probe of claim 22, furthercomprising a lumen extending through said probe tip and terminating atsaid irrigation port.
 24. The probe of claim 19, further comprising alumen extending through said probe tip and terminating at saidaspiration port.
 25. The probe of claim 19, further comprising acombined irrigation and aspiration port on said probe tip.
 26. The probeof claim 25, further comprising a lumen extending through said probe tipand terminating at said combined irrigation and aspiration port.
 27. Theprobe of claim 19, further comprising an electrical lead lumen extendingthrough said probe, which runs between a distal port and a proximalport.
 28. The probe of claim 27, wherein electrical leads extend betweensaid tissue ablator and said proximal port through said electrical leadlumen.
 29. The probe of claim 19, wherein said tissue ablator comprisesa cautery element.
 30. The probe of claim 29, wherein said cauteryelement comprises a radio frequency (RF) electrode.
 31. The probe ofclaim 19, wherein said tissue ablator comprises an ultrasoundtransducer.
 32. The probe of claim 31 wherein said tissue ablatorcomprises an array of ultrasound transmissive panels.
 33. The probe ofclaim 19, wherein said tissue ablator comprises a piezoceramicultrasound transducer.
 34. The probe of claim 19, wherein said tissueablator comprises a piezoelectric transducer having at least a firstelectrode on an exposed outer surface of said transducer.
 35. The probeof claim 19, wherein said tissue ablator comprises a cryogenic element.36. The probe of claim 19, wherein said tissue ablator comprises amonopolar electrode system.
 37. The probe of claim 19, wherein saidtissue ablator comprises a bipolar electrode system.
 38. The probe ofclaim 19, further comprising a power source.
 39. The probe of claim 38,wherein said power source is a current power source.
 40. The probe ofclaim 39, wherein said current power source provides radio frequencypower.
 41. The probe of claim 38, wherein said power source providesultrasonic energy.
 42. The probe of claim 38, wherein said power sourceprovides sonic energy.
 43. The probe of claim 38, wherein said powersource provides electrical power.
 44. The probe of claim 19, wherein aportion of the length of said probe tip is sized to fit within schlemm'scanal.
 45. The probe of claim 19, wherein said probe tip is hook-shaped.46. The probe of claim 45, wherein said tissue ablator is at the bite ofsaid hook-shaped probe tip.
 47. The probe of claim 19, wherein saidprobe tip is configured for goniectomy
 48. The probe of claim 19,wherein said probe tip is configured for schlemmectomy.
 49. A method fortreating glaucoma, comprising: inserting a probe into an eye; ablating aregion of the trabecular meshwork of said eye with said probe;aspirating said region of the trabecular meshwork of said eye with saidprobe; and removing said probe.
 50. The method of claim 49, furthercomprising irrigating said eye.
 51. The method of claim 49, wherein saidregion of the trabecular meshwork comprises at least half of saidtrabecular meshwork.
 52. A method for treating glaucoma, comprising:inserting a probe into an eye; aspirating a region of the trabecularmeshwork of said eye with said probe; and removing said probe.
 53. Themethod of claim 52, further comprising aspirating said region of thetrabecular meshwork of said eye from said eye.
 54. The method of claim53, wherein said region of the trabecular meshwork aspirated from saideye comprises at least 50% of said trabecular meshwork.
 55. The methodof claim 53, further comprising irrigating said eye.
 56. A probe for thetreatment of glaucoma, comprising: a probe tip configured to access thetrabecular meshwork; a tissue ablator disposed on said probe tip andconfigured to ablate said trabecular meshwork; an aspiration port onsaid probe tip; and a lumen extending through said probe tip andterminating at said aspiration port, wherein said probe tip isconfigured for goniectomy.
 57. The probe of claim 56, wherein saidtissue ablator is a cautery element.
 58. The probe of claim 56, whereinsaid tissue ablator is selected from the group consisting of a radiofrequency (RF) electrode, ultrasound transducer, array of ultrasoundtransmissive panels, piezoceramic ultrasound transducer, andpiezoelectric transducer.
 59. The probe of claim 56, further comprisingan irrigation port on said probe tip.
 60. The probe of claim 59, furthercomprising an irrigation lumen extending through said probe tip andterminating at said irrigation port.
 61. The probe of claim 56, furthercomprising an electrical lead lumen extending through said probe, whichruns between a distal port and a proximal port.
 62. The probe of claim61, wherein electrical leads extend between said tissue ablator and saidproximal port through said electrical lead lumen.
 63. The probe of claim56, further comprising a power source.
 64. The probe of claim 63,wherein said power source is selected from the group consisting of radiofrequency, ultrasonic, sonic, and electrical energy.
 65. A probe for thetreatment of glaucoma, comprising: a probe tip configured to access thetrabecular meshwork; a tissue ablator disposed on said probe tip andconfigured to ablate said trabecular meshwork; an aspiration port onsaid probe tip; an aspiration lumen extending through said probe tip andterminating at said aspiration port, wherein said probe tip isconfigured for schlemmectomy, said probe tip comprising two parallelarms, wherein a first arm is located directly above a second arm. 66.The probe of claim 65, wherein said tissue ablator is disposed on thelower arm of said probe tip.
 67. The probe tip of claim 65, wherein saidtissue ablator is a cautery element.
 68. The probe tip of claim 65,wherein said tissue ablator is selected from the group consisting of aradio frequency (RF) electrode, ultrasound transducer, array ofultrasound transmissive panels, piezoceramic ultrasound transducer, andpiezoelectric transducer.
 69. The probe of claim 56, further comprisingan irrigation port on said probe tip.
 70. The probe of claim 69, furthercomprising an irrigation lumen extending through said probe tip andterminating at said irrigation port.
 71. The probe of claim 56, furthercomprising an electrical lead lumen extending through said probe, whichruns between a distal port and a proximal port.
 72. The probe of claim71, wherein electrical leads extend between said tissue ablator and saidproximal port through said electrical lead lumen.
 73. The probe of claim56, further comprising a power source.
 74. The probe of claim 73,wherein said power source is selected from the group consisting of radiofrequency, ultrasonic, sonic, and electrical energy.
 75. A probe for thetreatment of glaucoma, comprising: a probe tip having a hollow chamberconfigured to access the trabecular meshwork; a rotatable shaft disposedwithin said hollow chamber; and a cutting head on the distal end of saidrotatable shaft.
 76. The probe of claim 75, wherein said hollow chamberis in fluid communication with an irrigation supply.
 77. The probe ofclaim 75, further comprising an aspiration lumen extending through saidprobe tip.
 78. A probe for the treatment of glaucoma, comprising: aprobe tip having a hollow chamber configured to access the trabecularmeshwork; a cutting sleeve disposed within said hollow chamber; and afootplate formed at the distal end of said probe tip.
 79. The probe ofclaim 78, further comprising a cutting blade integrally formed at thedistal end of said cutting sleeve.
 80. The probe of claim 78, whereinsaid cutting sleeve is hollow.
 81. The probe of claim 78, furthercomprising a combined irrigation and aspiration port.
 82. The probe ofclaim 81, wherein said hollow cutting sleeve forms an aspiration lumen,extending through said probe tip and terminating near said irrigationand aspiration port.
 83. The probe of claim 78, further comprising anirrigation lumen.
 84. A method for treating glaucoma, comprising:inserting a probe into an eye; mechanically cutting a region of thetrabecular meshwork of said eye with said probe; aspirating said regionof the trabecular meshwork with said probe; and removing said probe. 85.The method of claim 84, further comprising removing said region of thetrabecular meshwork of said eye from said eye.
 86. The method of claim84, further comprising irrigating said eye.
 87. The method of claim 85,wherein said region of the trabecular meshwork removed from said eyecomprises at least 50% of said trabecular meshwork.